Insecticidal spray compositions



Patented Oct. 6, 1936 UNITED STATE s PATENT OFFICE,

.INSEC'I'ICIDAL SPRAY COMPOSITIONS William Hunter Volck, Watsonville,Calif., assignor to California Spray-Chemical Corporation, Berkeley,Calif., a corporation of Delaware No Drawing.

Claims.

The invention relates to compositions useful film of the active materialon all of the surface 'of the host receiving treatment. When, as wasformerly the case, simple water'suspensions of such toxic agents weresprayed onto the fruit and foliage of an insect infested host, none ofthese conditions were substantially fulfilled; a large part ofthesuspended material ran off with the drip and such deposit as remainedwas only in patches and adhered only loosely so that the first wind orrain dislodged the major portion of it. Needless to say, the percentageof insect kill was seldom satisfactorily high.

It has also long been recognized by economic entomologists andhorticulturists that no single insecticidal substance and even furtherthat so no one type of insecticidal material is efiective against allthe insects that may infest a given host at the same time. Therecognition of this fact led at first to the practice of successivelytreating or spraying with difierent materials for the elimination ofdifferent types of insect pests. Such obviously wasteful expenditure oflabor naturally brought about many attempts to combine variously activeinsecticidal ingredients in the same preparation.

40 While this idea was simple and logical enough, its satisfactoryexecution was soon found to be complicated by many factors such aschemical and physical interaction between the various active ingredientsboth before and after application to the living host, so that thecombined effect of two ingredients when simultaneously applied wasseldom the sum of their respective effects when applied separately.Probably the most serious of all such factors had to do with damage tothe host occasioned by interaction between certain ingredients incomplex spray compositions after they had been applied.

During the early development of this basic idea of combining severalinsecticidally active incurred to me that the highly effective phyto--nomic petroleum oils such as those defined and described in my issuedpatents, #1,'707,465 and #1,'707.,468, might be applied together withlead 60 arsenate suspensions and that such combination gredients in thesame spray composition'it oc- Application February 3, 1934, Serial No.709,631

might result in an insecticidal preparation of extreme potency and ofvery wide usefulness.- It further appeared that the oil, in addition toits own inherent insecticidal action, might contribute just the stickingaction necessary to ef- 5 fect a more satisfactory retention of leadarsenate on the sprayed surfaces.

Extensive tests on a commercial scale soon 5 demonstrated that this hopewas probably realizable though the combination was not entirely 10 freeof complicating difliculties, such as those just enumerated. It was, forinstance, found that when a quantity of phytonomic petroleum oilemulsion containing certain emulsifiers was added toa lead arsenatesuspension a heavy and, 15 adherent deposit of arsenate was produced. IThis combination was found to be very,=satisfactory-in more or less aridregions such as the apple districts of the Pacific Northwest, but

when applied in more humid climates it pro- 20 duced an undesirableamount of arsenical injury in the form of withering and foliage burn. Atthat time it was the general practice to employ alkali soaps, alkalicaseinate and various other alkaline reacting emulsifiers in pre- 25paring spray oil emulsions and often still further to increase thealkalinity of the resulting dilute emulsion through the use of ammoniaas a preservative when caseinate was used as the emulsifier. In thelight of a theory, which was 0 then prevalent, tothe effect that foliagedamage from lead arsenate was due to the liberation of soluble arsenicthrough excess alkalinity, it appeared that in order safely to apply anoil emulsion together with lead arsenate sus- 35 pensions, newemulsifiers for the oil would have to be found which were not onlyneutral when applied but which could be counted upon to remain so.

It furtherdeveloped during the course of these 40 early experiments thatwhile a heavy adherent film of arsenate resulted from the use of themineral oil emulsions which we were then supplying to the trade thedeposit was neither as uniform in thickness nor as complete in its cov-5 erage as was to he desired. It thus appeared that in order to improvethe action in this respect preparations with better wetting andspreading characteristics would have to be pro vided. 59

In order thus simultaneously to realize the fullest advantages of aphytonoinic petroleum oil emulsion spray and a lead arsenate suspensionwithout danger of substantial host damage from the combination, aneutral spray conditioning composition possessing emulsifying, wetting,spreading, fiocculating and sticking properties, each to a high degree,was needed.

It was further apparent that such material or composition must inaddition be compatible inso wastobeput.

It is common practice in the distribution of my previously describedphytonomic petroleum oil emulsions to market the oil in concentratedemulsion form containing 75% or more of oil, such emulsions beingdiluted to the proper extent by the user. It is usually convenient toeffect this dilution by adding the concentrated emulsion to anappropriate quantity of water in the tank of the spray apparatus Justprior to the start of the spraying operation. In order to facilitatethis tank mixing operation it is desirable that the concentrated oil inwater emulsion marketed shall not be still and Jellylike but rathershall be readily fiowable. A high degree of'flowability of sucha productis all'the more desirable when it is to be used in conjunction withaqueous suspensions of solids such as lead arsenate, since a completeand uniform dispersion of the oil droplets is necessary in order thatthey may become properly associated with the suspended particles ofsolid and may thus result in a smooth and uniform film of oil and solidson the surfaces receiving spray treatment.

It was further discovered, timing the endeavors to render oil emulsionsand lead arsenate suspensions applicable in the same spray, that inorder for the oil and solid to become prop.- erly associated and byproper flocculation to form asatisfactory deposit a fatty acid soapappeared to be a necessary constituent of the emulsifier used inpreparing the concentrated oil emulsion. Since the fatty acid soaps thenin, use were well known to hydrolyze .to give alkaline solutions which,as previously pointed out, are undesirable for use with lead arsenate adifferent or at least a modified soap was needed in order to makepossible the realisation of our ultimate purpose.

-It is the object of this invention to-provide a new composition ofmatter, for use particularly in insecticidal spray preparations, whichshall possess the foregoing emulsifying. wetting, spreading,fiocculating and sticking characteristics and shallatthesar'netimebefreefrom any injurious effect on growing'foliage whenused with a lead arsenate or similar insecticidal solid suspended inwater or when applied with an emulsion of a phytonomic petroleum oil inwater or when used with both suspended in the same aqueous spray medium.

It is another object of this invention to provide a concentratedemulsion of a phytonomic oil in water which can be effectively and eco-.nomicaliy combined in insecticidal spray application with such powerfulsolid as. lead arsenate.

Still other objects contributory to the broad success. of the inventionwill be obvious to one skilled in the art both'from the foregoingintroductory discussion and from the description Presented hereinafter.

In the simultaneous application of an oil emulsion and asuspended solidin a combination insecticide it is necessary for satisfactory operationthat the oil remain highly dispersed and the solid completely suspendeduntil the spray composition strikes the infested leaf, stalk or fruitwhereupon it becomes necessary that the emulsion shall break quickly andcompletely and that the suspended solid be thrown out of suspension orflocculated immediately in order that they shall not be carried away bythe water which collects and; drips 011. Having quickly. flocculatedand/or coagulated both the oil and the solid matter is, however, usuallynot enough to insure their most economical utilization. A material whichwill tend to stick both the phytonomic oil and the solid insecticide inplace yet which will cause them to spread rapidly over the whole surfacetreated and to penetrate readily into every crevice and irregularity insuch surface is also essential.

' Whenever it becomes necessary or even desirable to provide acomposition of matter having a multiplicity of functions as diverse asthose above recited, i. e. emulsifying, wetting, spreading,flocculating, sticking, etc., it is usually necessary to synthesize sucha composition from several separate ingredients each of whichcontributes its own particular characteristic or characteristics to .insuch manner as to produce the delicately balanced system required. A

As previously pointed out one of the prime requisites for anemulsifying. wetting, spreading. sticking, composition to be used withoil-lead arsenate compositions is acid-alkali neutrality.

Neither the ordinary alkali soaps or the caseinates which havepreviously been used as emulsifiers meet such a requirement and yet bothsoap and a casein constituent are desirable components of a sprayconditioning preparationbecause of certain of their other properties. Infact,- as previously remarked, and as demonstrated by ammonia orappropriate organic bases.

As an example of such a composition and a method whichI havefoundsatisfactoryin its preparation the following example is given:

The caustic is dissolved in one-half the watera'nd the first portion ofoleic acid is mixed with the other half at about 50 C. These two aqueoussolutions are then mixed with vigorous agitation.

After cooling the second portion of oleic acid is added and dispersed byvigorous circulation. The

- While we have customarily use'd potassiumoleate as the neutral soap inour tests it will be readily apparent to those skilled in the art thatother soaps might be prepared by an analogous method which would besubstantially neutral to phenolphthalein and equally satisfactory in allother respects.

Such a soap solution containing from -30% by weight of soap material and80-70% water will hereinafter be referred to merely as neutral soapsolution".

In providing the other necessary ingredients of 5 my complex sprayconditioning composition I have found that certain sulfonic saltsincludin the water soluble petroleum sulfonic salt preparation which wasdescribed in my recent patent,

#l,922,607, as a powerful bland, neutral, emulsify- 0 ing, wetting andspreading agent, have an added property which makes them especiallyuseful in the present connection.

As previously mentioned casein has emulsion stabilizing characteristicsand also spreading and 5 sticking power, all of which are particularlydesirable in the .present composition. Casein in anything but alkalineform is, however, not water soluble and since alkaline reactingcompounds must be rigorously excluded from compositions designed for mypresent purpose casein appeared to be barred.

It has, however, developed that by proper coaction of a neutral sulfonicsalt material, and especially the one which I have prepared frompetroleum oils, with free neutral casein, both pass readily into clearneutral aqueous solution and constitute 'a second stock preparationuseful in the ultimate production .of my spray conditioning material. Asillustrative of the pro- 4 portions of ingredients to be used and theirExAMPLs #2 Casein-sulfonic salt solution Pounds. Casein 468 Water 2 592Sulfonic salt solution 2616 method of combination, the followingspecific example is given:

the boiling point until the casein goes completely into solution. Thesulfonic salt solution'contains about 30% (wt.) of the alkali salts ofthe sulfonic compounds previously described, 20% inert material and 50%water. A solution prepared according to the foregoing example willtherefore contain approximately 30-35% by weight of casein and sulfonicsalt and 70-65% water, though such concentrations appear to have noparticular significance and are employed merely for convenience incompounding. It has been found that a weight ratio of sulfonic salt tocasein of about 0.75 to 1.00 is necessary to eifect solution of thecasein. Higher ratios may often be desirable. I have sometimes employeda ratio as high as 5.0 to 1.0.

A stock solution of casein-sulfonic salt in the proportions and at theconcentrations just given 70 will hereinafter be referred to as a liquidspreader.

When this liquid spreader is mixed with substantially an equal volume ofneutral soap solution a product is obtained which, while of par- 5ticular advantage in connection with horticul- These materials areheated together, just below lating and sticking the solid components ofaqueous suspension sprays in general and particularly such suspensionsas the fluorine compounds, fiuosilicates and the lead-arsenic compounds.Its most outstanding present contribution to the insecticidal art is,however, in making possible.

, the combination in the same spray of an alkali sensitive insecticidalmaterial and a petroleum oil with a minimum of damage to the sprayedhost and with a highly satisfactory deposition and retention of theinsecticidal ingredients.

Another advantage of my composition is that it may be used as theemulsifier, stabilizer, etc.,

\ in the concentrated phytonomic petroleum oil emulsions of commercewhich are to be employed alone and for their own particular properties,or it may be used in other concentrated emulsions designed primarily tobe used in securing the foregoing advantages in the deposition ofarsenate of lead or other solid insecticidal ingredients. The onlysubstantial diiference being that in such latter emulsions a somewhathigher ratio of conditioning agent to oil is employed in theconcentrated emulsion as will be more clearly brought out by thespecific examples hereinafter provide'd.

Still one further discovery constitutes a part of my present invention.As is well known in industry any preparation containing casein or itsderivatives is readily attacked by destructive organisms and unless usedimmediately must be protected by a preservative agent.- Ammonia,formalin and many other similar preservatives have previously been usedin this connection.

- For my present use I have selected cresylic acid as possessing therequisite high perservative power, being non-injurious to plant lifewhen applied in moderate to low concentrations and being neutral or acidin reaction. In addition to these well known properties I have nowdiscovered that by the inclusion of a quantity of cresylic acid in myconditioning composition which is then used in the preparation of astandard commercial concentrated (83%) phytonomic oil emulsion, a resultis produced which was not to have been expected. Such as emulsion isconsiderably softer and more flowable than when no cresylic acid isincluded, Flowability in such a product is, as previously remarked, ahighly desirable characteristic much appreciated by the operator whosetask it is to prepare the final spray preparation in the spray tank orequivalent apparatus.

The inclusion of cresylic acid in varying amount in my formula thus notonly serves to preserve the casein but also permits of. the readycontrol of one of the important physical properties of concentrated oilemulsions prepared with it.

My complete spray conditioning composition which possesses emulsifying,wetting, spreading, flocculating and sticking characteristics invariable degree and in balanced relation, is neutral, harmless tovegetation and inexpensive to produce, thus consists essentially ofneutral soap, liquid spreader, and water with cresylic acid when and asrequired. Its properties are variable these essential ingredients whichmay be between rather wide limits, the particular balance of propertiesrequired for any given purpose determining the exact proportions to beemployed.

In order that my invention may be better understood, one of its manyapplications is illustrated by the following specific example in whichit is employed in the preparation 'of a concen-- trated emulsion of aphytonomic petroleum spray oil useful in the application of leadarsenate the combined aqueou's solutions of the conditioning agents. Bycalculating back to the ultimate tompositions of the stock solutions aspreviously'given, it will beseen that suchan emulsion what less of theemulsifying and conditioning" concentrate would thus contain:

. Per cent by weight Neutral soap constituents 3.8

Casein 1.3 Sulfonic salts 2.1 Inert material 1.5 Water 7 20.0 Oil "71.3

For other purposes and with oils of'diifer'ent gravities very differentproportions of conditioningagent, oil and water may be employed. Forinstance, in an emulsion to be used alone and not as a carrier forarsenate or other suspension somematerials maybe used.

Example #4 Oil emulsion concentrate r Gallons Neutral soap soilution12.5 Casein-sulfonic salt solution 12.5 Cresylic acid -e 2.0 to 8.0Water- 105.0 Calol spray oil #1 (light) 700.0

In this case the ultimate composition by weight would be:

Per centby weight Soap I constituents 0.45 Casein 0.16 Sulfonic salts0.44 Cresylic acid; .28 to 1.2 Water. 16.73 Oil in 81.94

The amount of cresylic acid to be included in the conditioningcomposition for preservative purposes should be suflicient togive aconcentration of 0.2 to 0.5% in the emulsion concentrate.

When advantage is to be taken of the fluidity imported by this materialto the emulsion it may be present to 5.0% or more oi; the finishedemulsion.

As an illustration of the very real value of my v spray conditioningcomposition its use in a preparation for the simultaneous application ofoil and lead-arsenate is typical.

When one quart of the emulsion of Example #3 and 4 lbs. of commerciallead arsenate were mixed with gallons of water in a spray tank andapplied to apple trees, lead arsenate was found to be retained on theleaves to the extent of 112 milligrams per square inch of surfacewhereas the customary lead-arsenate and fish oil app ication left only57 milligrams of the solid arsenate on a similar surface area.

The economic value of my invention in thusincreasing the emciency ofutilization of lead arsenate substantially 100% is easily measurable.

Its value when used with oil emulsion sprays alone is not so readilymeasurable but is no less real when judged by the improved operationwhich has been uniformly realized wherever tests have been made.

Having now described my invention in detail and taught how it maybeutilized, I claim:

1. An insecticidal spray conditioning composition useful in preparinghorticultural sprays, said composition comprising a fatty acid soap ofan alkali metal in which the acid is in suiiicient excess over thealkali to insure substantial neutrality to phenolphthalein, casein andpetroleum sulfonic salts, all in aqueous solution.

2. An insecticidal spray conditioning composition useful in preparinghorticultural sprays, said composition comprising a fatty acid soap ofan alkali metal in which the acid is in excess over the alkali, caseinand petroleum sulfonic salts all in aqueous solution which issubstantially neutral to phenolphthalein on dilution. I

3. An insecticidal spray conditioning composition useful in preparinghorticultural sprays, said composition comprising a fatty acid soap ofan alkali metalin whichthe acid is in sumcientexcess over the alkali toinsure substantial neutrality to phenolphthalein, casein, petroleumsulfonic salts and cresylic acid, all in aqueous solution.

4. An insecticidal spray conditioning composition as in claim 1, whereinthe soap is potassium oleate containing excess oleic acid.

5. A concentrated emulsion of insecticidal mineral oil dispersed in theaqueous solution of claim 3.

6. An' insecticidal spray composition, useful in horticultural pestcontrol, which comprises emulsifle'd mineral oil, a fatty acid soapof'an alkali metal which soap is neutral to phenoiphthaiein due to anexcess of the fatty acid, casein and water soluble petroleum sulfonicsalts. 7. An insecticidal spray composition, useful in horticulturalpest control, which comprises emulsifled mineral oil, a fatty acid soapof an alkali metal which soap is neutral to phenolphthalein due to anexcess of the fatty acid, casein, water soluble, petroleum sulfonicsalts and an alkali sensitive stomach or contact poison for insects.

8. An insecticidal spray composition as in claim '7 wherein the alkalisensitive component is lead arsenate.

9. An insecticidal spray composition as in claim "I, wherein the alkalisensitive component is an inorganic fluorine compound.

10. An insecticidal spray composition as in claim7 wherein the alkalisensitive component is a derivative of a substance selected from a groupcomprising pyrethrum, derris and cube. K g

' WILLIAM HUNTER 'VOICK."

